Albumin [al BYOO min]: a protein in the serum that transports substances such as drugs and prevents leakage of fluid into the surrounding tissues.

Alkaline phosphatase [AL kuh lin FAHS fah tays]: protein found in bile duct cell membranes; blood levels may be increased in any liver disease, but more markedly with cholestasis.

Alhph 1 - antitrypsin [AL fah -1 an tigh TRIP sin]: plasma protein produced by the liver that inhibits the activity of trypsin and other proteolytic enzymes; inherited deficiency leads to emphysema and sometimes cirrhosis.

Aminotransferase [ah MEE noh TRANS fir ays]: hepatocyte enzyme that modifies proteins; blood levels increase in the setting of hepatocellular necrosis (hepatocyte death). The two aminotransferases important in liver disease are AST (aspartate aminotransferase) and ALT (alanine aminotransferase).

Antibodies: proteins produced in response to a specific antigen, which can then combine with that antigen and neutralize it.

Antigens: a molecule with a specific configuration that is recognized by the immune system; usually part of a protein or sugar. It stimulates the formation of a specific antibody and can elicit an allergic reaction, or otherwise trigger an immune response.

Ascites [uh SIGH teez]: accumulation of fluid in the abdominal cavity, usually secondary to liver scarring and increased sinusoidal pressure. Intractable ascites is unresponsive to treatment and continually recurs.

Autoimmunity [AW toh im MEWN it ee]: a state or disease in which the body's immune system attacks the body's own tissues.

Bile: greenish fluid formed by the liver and emptied into the small intestine via the bile ducts; contains bilirubin, bile salts, phospholipids, and cholesterol.

Bilirubin [BIL ee roo bin]: a bile pigment cleared from the bolld by the liver; formed as a breakdown product of old red blood cells; marked increase in blood levels can lead to jaundice from deposition of bilirubin in skin, mucous membranes, and whites of the eyes.

Caput medusae [KAP ut muh DOO see]: literally "Medusa's head"; dilated, varicose veins around the umbilicus, which may be seen in patients with cirrhosis of the liver.

Ceruloplasmin [suh ROO loh PLAZ min]: copper transporter protein; blood levels are usually decreased in Wilson's disease.

Cholestasis [hoh luh STAY sis]: blockage or suppression of bile flow, from either intrahepatic or extrahepatic causes.

Cirrhosis [sur ROH sis]: pathologically-defined disease characterized by diffuse, irreversible fibrosis of the liver surrounding regenerative nodules.

Coagulopathy [koh AG yoo LAH puh thee]: increased bleeding tendency due to decreased hepatic synthesis of clotting factors.

Decompensation: failure of the liver to compensate for damage or injury, resulting in a decrease in liver functions.

Dysplasia [dis PLAY zhuh]: alteration in size, shape, and organization of cells; may be precursor of cancer.

Encephalopathy [en SEF uh LAH puh thee]: alteration in sleep patterns and mental status, ranging from forgetfulness and mild confusion to coma; may be caused by circulating gut-derived brain-toxic proteins not cleared by a dysfunctional liver.

Fibrosis [figh BROH sis]: the formation of fibrous tissue, or scarring.

Fulminant: running a speedy course, with rapid worsening.

Hemochromatosis [HEE moh KROH mah TOH sis]: toxic accumulation of iron in organs leading to dysfunction, including cirrhosis; may be genetic (inherited increase in gut iron absorption) or a result of massive blood transfusions.

Hepatitis [HEP uh TIGH tis]: inflammation and damage to the liver; generally considered acute if duration is less than 6 months, chronic if greater than 6 months.

Hepatocellular necrosis: localized tissue death of hepatic cells.

Hepatocellular carcinoma (HCC): a primary liver tumor more common in patients with cirrhosis.

Hepatocytes: liver cells.

Hepatorenal [HEP uh togh REE nahl] syndrome: poorly understood terminal kidney failure in the setting of hepatic disease.

Homeostasis [HOH mee oh STAY sis]: tendency of the body to maintain a stable internal environment, using a variety of counterbalancing control systems.

Hyperbilirubinemia [HIGH pur BIL ee roo bin EE mee uh]: abnormally high levels of bilirubin in the blood.

Icterus: see Jaundice.

Idiopathic [ID ee oh PATH ik]: autoimmune chronic active hepatitis

(IACAH): chronic hepatitis of unknown origin; associated with a variety of anti-self antibodies; progresses to cirrhosis and decompensation unless treated with corticosteroids.

Jaundice [JAHN dis]: hyperbilirubinemia, with deposition of bile pigment in the skin, mucous membraes, and sclerae (whites of eyes), resulting in a yellow appearance of the patient; also called icterus.

Kayser-Fleischer rings: golden-brown rings in the corneas due to copper deposition in Wilson's disease.

Kupffer cells: "scavenger" cells that remove foreign matter, worn-out blood cells, and bacteria from the liver.

Limiting plate: layer of hepatocytes surrounding each portal triad and separating it from the surrounding sheets of hepatocytes.

Lobule [LAHB yool]: "structural" unit of the liver; shaped like a hexagon on cross section, with six portal triads at the periphery and a central vein.

Portal hypertension [POR tahl HIGH per TEN shun]: abnormal increase in portal blood pressure, usually due to obstruction of, or increased resistance to, portal blood flow.

Portal system: includes all the veins that drain the small and large intestines, stomach, and spleen and that converge into the portal vein to drain into the liver.

Portal triad (or tract): consists of three components: branch of the hepatic artery, branch of the portal vein, and a biliary duct, all held tightly together by a limiting plate of hepatocytes at the periphery of the lobule.

Portosystemic [POR toh sis TEM ick] shunting: development of blood vessels that connect the portal and systemic circulation while bypassing the liver.

Prognosis: prediction as to the probable outcome of a disease.

Prothrombin [proh THRAHM bin] time (PT): laboratory test that measures the clotting of blood in seconds; abnormally increased PT signifies bleeding risk due to deficient synthesis of clotting proteins.

Pruritus: itching.

Seroconversion: appearance of specific antibodies in the blood, indicating recovery from infection or successful vaccination.

Sinusoids: tunnels through hepatic tissue allowing exchange of nutrients and other substances between blood and hepatocytes.

Spider angiomas: red capillary tufts in the skin that blanch on pressure; often found in patients with cirrhosis.

Spontaneous bacterial peritonitis (SBP): bacterial infection of ascitic fluid.

Steatorrhea [STEE uh toh REE uh]: decreased absorption of dietary fats, resulting in their passage to the distal bowel which causes foul-smelling diarrhea; can be caused by deficiency of bile salts.

Transaminase: see Aminotransferase.

Varices [VAYR ih seez]: dilated veins; lower esophageal varices form as collaterals from portal hypertension and can rupture, leading to massive bleeding.

Wilson's disease: inherited metabolic disorder in which copper accumulates in the liver and in the central nervous system, causing hepatitis, cirrhosis, and neuropsychiatric symptoms.

Information provided by The Hepatitis Information Network (www.hepnet.org)]